Continuously monitoring a patient's physiological condition generally requires the patient's hospitalization, usually at great cost, especially where long term monitoring is required. In some circumstances a wide variety of out-patient monitoring devices may be used to monitor the physiology of patients who are physically outside of the hospital. Some out-patient monitoring devices have a limited range of operation, requiring monitored patients to remain close to a receiving station and thus limiting his mobility. Other devices are adapted for monitoring mobile or ambulatory patients while they move about in a vehicle or on foot and have a wide range of operation.
One such group of devices includes holter devices which generally record a patient's physiological data, such as the patient's ECG, during predetermined period of time for examination at later time. Other devices include event recorders. These devices provide for the capture of a patient's physiological data during a physiological “event,” such as a cardiac arrhythmia or an episode of patient discomfort. These devices may be patient activated or activated automatically when physiological data are detected which meet predefined event criteria.
Holter devices and event recorders typically require that a patient return to the hospital periodically in order to transfer the recorded data. Some of these devices provide for transmission via telephone or other communications facilities to a remote location for interpretation by a clinician. These devices generally require additional communications and medical testing devices to be present at patient location. In the case of event recorders, unnecessary delay between event recording and transmission is often introduced where such additional devices are not present during the event.
The mobility of high-risk patients must be weighed against the need to monitor a patient's location in order to provide a patient with emergency medical attention should a dangerous event occur.